As is known, intramedullary rods (also referred to as intramedullary nails) are used in orthopedics to align and stabilize fractures. Such rods are typically inserted into the bone marrow canal or bore in the center of the long bones of the extremities (e.g., the femur or tibia). One of the significant advantages of such rods over other methods of fixation is that they share the load with the bone, rather that entirely support the bone. Because of this, patients are able to use the extremity more quickly. Typically such rods are fixed in position via the use of transversely extending locking screws. While generally effective for its purpose, transversely extending screw-based fixation techniques have drawbacks, namely, placement and fixation is relatively difficult and time consuming and as a result the patient will be exposed to larger doses of radiation resulting from the imaging procedure during the rod's placement and fixation. Moreover, the use of transversely extending locking screws places unnecessary stress at the screw contact points.
Accordingly, a need exists for an intramedullary device that overcomes the disadvantages of the prior art.
The subject invention addresses that need by providing an intramedullary device which obviates the need for transversely extending locking screws and their attendant problems. Thus, the device of this invention enables its placement and fixation to be accomplished in a shorter period of time than with prior art devices. Moreover, due to its biomechanical properties the device of this invention exhibits a more even distribution of stress along its length, thereby facilitating faster healing. Further still, dynamization (i.e., the promotion of bone healing in fractures by allowing some movement or compressive loading) begins to occur from the first day of fixation to thereby further enhance the rate of healing and callus formation and without scarring of the skin as has characterized the to prior art.